Control system for aircraft refueling facilities

ABSTRACT

A petroleum-oil-lubricant hydrant facility control system which utilizes reed proximity switches and magnets as a replacement for unreliable cables, sockets, plugs and switches of currently utilized control arrangements without requiring major modifications of the hydrant facility junction box. The magnetic reed switch is mounted to one side of a plate and a magnetic field is applied to the other side of the plate to cause actuation of the switch. The magnetic field producing means may be mounted on a cover to provide emergency stop control.

United States Patent [191 Baker [4 1 Oct. 14, 1975 CONTROL SYSTEM FOR AIRCRAFT REFUELING FACILITIES [76] Inventor: George 0. Baker, 8 Hillcrest Drive,

Rochester, NH. 03867 [22] Filed: Dec. 11, 1973 [21] Appl. No.: 423,876

[52] US. Cl. 340/252 R; 335/205 [51] Int. Cl. G08B 21/00 [58] Field of Search 340/252 R, 25, 26;

ZOO/61.62, 61.63, 61.69, 61.7; 335/205, 206, 207; 174/52 R [56] References Cited UNITED STATES PATENTS 3,239,961 3/1966 Forkner 335/207 X 3,590,321 6/1972 Scheidweiler et a1 ZOO/61.62 X 3,636,485 l/l972 Weathers 335/205 Primary Examiner.l0hn W. Caldwell Assistant Examiner-Daniel Myer Attorney, Agent, or Firm-Joseph E. Rusz; Sherman H. Goldman ABSIRACT A petroleum-oil-lubricant hydrant facility control system which utilizes reed proximity switches and magnets as a replacement for unreliable cables, sockets, plugs and switches of currently utilized control arrangements without requiring major modifications of the hydrant facility junction box. The magnetic reed switch is mounted to one side of a plate and a magnetic field is applied to the other side of the plate to cause actuation of the switch. The magnetic field producing means may be mounted on a cover to provide emergency stop control.

9 Claims, 7 Drawing Figures MAGNET MARKER DISCS LIGHT BULB MAGNETIC REED SWlTCH U.S Patent Oct. 14, 1975 Sheet10f3 3,913,083

FIG ,1

PRIOR ART 'FIE ,2 PAP/07?? US. Patent Oct. 14,1975 Sheet2 01-3 3,913,083

MAGNET MARKER DISCS MAGNETIC REED SWITCH LIGHT BULB US Patent Oct. 14, 1975 Sheet30f3 3,913,083

MAGNETIC REED SWITCH CONTROL SYSTEM FOR AIRCRAFT REFUELING FACILITIES BACKGROUND OF THE INVENTION This invention relates generally to POL (petroleumoil-lubricant) systems and more particularly to an improved control system for aircraft refueling facilities which utilizes magnetic switches in order to avoid the difficulties encountered in the prior art.

Present refueling and defueling control systems used with Pritchard or Panero pump house arrangements require costly maintenance,-especially when usage occurs under less than optimium conditions. The principle difficulty with the control systems occurs with three components, the portable operating cord with its associated elements, the emergency stop buttonand the sockets housed in the junction box which is installed in the concrete apron at the hydrant outlet locations of the refueling facility. Analysis of one large pumping facility showed very high repair costs for the junction box components and replacement of the operating cords not to mention the lost hours experienced by the constant need for repair at each hydrant-outlet. This invention eliminates the cord with its associated components, the conventional emergencystop button and the defuelrefuel sockets at the junction box and replaces these elements with a system with improved features which is safer, and more'eco'nomical since it provides a reduction in original installation as well as maintenance and repair costs. Additionally, it was found that under adverse weather conditions wherein ice, high humidity or cold were present, operation utilizing conventional components was inhibited. These conditions, however, did not produce a derogation of operability of the components of this invention.

SUMMARY OF THE INVENTION The control system for aircraft refueling facilities as contemplated by this invention eliminates cords, sockets, plugs and switches, which have caused difficulty in the past, and substitutes therefor a foolproof, safe, reliable, economical system which solves the difficulties of the prior art.

Accordingly, it is a primary object of this invention to provide a refueled fuel control system which is easy and economical to produce of standard, conventional, currently available materials that lend themselves to mass production manufacturing techniques.

It is another object of this invention to provide a refueling and defueling control system which operates under adverse weather conditions with improved reliability.

It is still another object of this invention to provide a refuel and defuel control system for aircraft refueling facilities which provides for improved safety.

It is a further object of this invention to provide a refuel-defuel control system which is simple to operate and has the exposed portions of its elements at zero potential, thereby making it ideally suitable for electrical operation in hazardous environments.

It is a still further object of this invention to provide a refuel and defuel control system which minimizes abuse by inexperienced operators by having an indicator system which is fail safe to enable visual perception of the functioning of the system.

Another object of this invention involves the provision of a control system having an emergency stop action which is faster and more reliable than that currently utilized, since stop action occurs by lifting the emergency stop cover without requiring additional manual operation of a switch.

Still another object of this invention involves the provision of a switching control system for refuel and defuel systems which eliminates the need for large amounts of force for switch operation.

A further object of this invention involves the provision of a control system for aircraft refueling facilities which eliminates corrosion problems found in existing systems which utilize aluminum switch bodies mounted in a cast steel junction box in environments containing moisture.

A still further object of this invention involves the provision of a new control system which is adaptive to a modular arrangement and with minor changes in the magnetic switch could be modified for increased functions.

These and other advantages, features and objects of the invention will become more apparent from the following description taken in connection with the illustrative embodiment in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view ofajunction box having a refueled fuel, under apron control system;

FIG. 2 is a cross section of the junction box illustrating the arrangement of parts found in the prior art;

FIG. 3 is an exploded view of the elements of the control system of this invention which may be applied to either or both of the refuel and defuel portions of the junction box, however, the appropriate connections of the wires for the electrical elements are pictorially illustrated;

FIG. 4 is an end view of the parts illustrated in FIG. 3 shown in their assembled position;

FIG. 5 is a perspective view of the junction box showing the system of FIG. 4 installed in the box;

FIG. 6 is a pictorial representation of the emergency control switch arrangement of this invention; and

FIG. 7 is an illustration in cross section'of the cover modification for the emergency control section.

DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is made to FIG. 1 and FIG. 2, the internal components of which illustrate the prior art POL system which requires an electric cable for its operation. There is shown in these Figures a water tight junction box 10 of the genre manufactured by Crouse-Hinds, type AAP-72, which includes a cover body 11 and nonmagnetic, cast aluminum covers l2, l4 and 16 which are rotatable by means of bronze hinge elements l3, l5 and 17, respectively. The covers provide protection for electrical sockets l8 and 20 and emergency stop switch 22. The sockets l8 and 20 are each used with a portable remote control cable (not shown) which consists of a switch integrally molded into a neoprene jacketed housing with an electric cable from the switch to a plug at the opposite end of the cable which is adapted to mate with a fueling or defueling receptacle socket 18 or 20 at the junction box located at each refueling hydrant.

It has been found that forces of more than 20 pounds are often required for thumb or finger pressure to operate the switch on the cable in order to turn the refueldefuel pumps onor. off. Since the switches are ofttimes used in cold climate under adverse weather conditions, the cables were found to be relatively unreliable and difficult to use, especially when ice is present.

Connected withreceptacles or sockets 18 or 20 and emergency control switch 22 are wires 23 which lead from these elements to a terminal block 24 which in turn provides connection with electric cables 26 which lead to the pump houseof the.POL system. The system thus far described is embedded in a concrete apron 28 (FIG. 2) of a flight line and is shown in sealing relation with the concrete by means of O-ring 30.

In addition to. the difficulties encountered with the remote cables and their connectors the prior art emergency stop switches22 had an aluminum .body and were in contact with thecast, steel forming the cover body 11 of the junction box 10. In the presence of moisture, corrosion-due togalvanic action caused separation of the switch bodies from the button shafts. Be-

cause of difficultiescausedby the switch, unsafe conditions have been uncovered where bypassing of the stop buttons has occurred, thereby necessitating compensation in the safety procedural operations to maintain system usability.

The prior-a'rtsystem also was found to cause excessive wear on the pumps due to the fact that operation of the pumps could only be. felt by vibration of the fuel hose which is attached to the aircraft fuel cell. An indicator system inhibits the jockeying of pumps from on" to ,of in order to-produce a greater feel for the on operation of-the pumps. Elimination of the cable also eliminatesthe problems caused .by the'deliberate shorting of thesocket to obtain system, operation when a cable .was found to be defective.

The system of this invention modifies the prior art by utilizing the structure to be described relative toFIGS. 3 through 7. Modification of the system for the refueling and/or defueling operation involves the removal of sockets l8 and20 from the junction box and installing the structure illustrated in FIGS. 3 and 4. The substitute switching systemcomprises a circular stainless steel plate32 to which a neoprene sponge gasket 34 is cemented to provide a seal between the cover 12 and the switch unit. Two half inch diameter pieces of galvanized (ferric) steel 36 are epoxy bonded to the top surface of the stainless steel plate to provide a marker for placementof an actuating magnet 38 and acts as a detent so that the magnet 38 holds the on position. A hole 39 is provided in the stainless steelplate 32 to enable the utilization of a visual on-off indication of actuation of the fuel or defuel pumps to the pump house. The unit which is; bonded beneath the plate 32 comprises a magneticreed switch 40 which may be of a type manufactured by Microswitch or Hamlin model SRR-2. The magnetic reed switch is epoxy bonded as illustrated in FIG. 4 to the plate and is in series with a parallel circuit, as pictorially depicted in FIG. 3. This circuit comprises a 22 ohm, 2 watt resistor 42, a 5,000 pica farad voltage surge limiting capacitor 44 and a 3.2 volt, 350 milliampere bulb 46. Lead 45, which is connected to one side of the reed switch 40, and lead 47, which is connected to that side of the parallel circuit not connected with the reed switch, are available for connection through terminal block 24 with one of the cables 24 to the pump house for operation of a refuel or defuel relay coil. A 360 refractive index lens 48, such as a standard, crystal marble, is epoxy bonded or otherwise secured to the plate 32 at the hole 38and has the bulb 46 secured thereto in any conventional fashion such as by means of a RTV silicone. Of course, solder or crimp or other connectors could be utilized to secure the parallel circuit to the reed switch and for connection to the terminal block. The particular means utilized is not considered a part of this invention. The unit is shown assembled, for example, by RTV silicone, to the body 11 in- FIG. 5.

The emergency stop switch- 22, illustrated in FIG. 2, may be replaced by the assembly of FIG. 6 in order to avoid the problems previously mentioned with regard to theprior art. The embodiment of FIG. 6 illustrates a circular stainless steel plate 50 to which a magnetic qreed switch 52 is epoxy bonded to the underside. The

emergency cover 16 is illustrated in FIG. 7 and has a recess 54 cut therein with a magnet 56 bonded to the recess, for example, by means of RTV silicone such that closure of the cover'l6 causes the magnet 56 to rest on the plate 50, thereby keeping the normally open SPST magnetic reed switch 52 in the closed position. Emergency stop action occurs when the cover 16 is lifted thereby separating the magnet 56 from the reed magnetic switch 52.

--Operation1of themodified junction box for either refueling or defueling is achieved byv placement of magnet.38.o,f FIG. 3 over the metal discs 36 of the appropri-v ate sectionof the junction box 10. The discs position cause the magnet to operate the reed switch 40 to close the contacts therein, and at the same time, by magnetic attraction, provides an operating detent function to insure a positive on-result until manually removed. This action causes operation of a relay (not shown) located at the POL pump house. Since the parallel circuit, comprising the resistor 42, capacitor44 and bulb 46, is in series with the reed switch 40, current flowing through the relay coil at the pump house caused the closure of switch 40 also causesoperation of bulb 46 to indicate operation of the relay. If desired, a lanyard 60 maybe affixed to the magnet 38 for.remote operation of the magnet from the on position to the off position. The nonmagnetic cover 12 or 14 would providethe stop action for the magnet 38 when it hits the inner lip of the closed cover. The. operation of the emergency stop mechanism is obvious since the magnet reed switch 52 replaces the push button stop switch 22 of the prior art. Only elimination of the additional pressing action on the button of the switch 22 of the prior art device is effected.

Although this invention has been described relative to particular embodiments, it should be understood to those skilled in the art that the invention is capable of variety of additional embodiments within the spirit and scope of the appended claims. For example, the particular values ofthe resistor and capacitor and their mode of connection as well as the utilization of epoxy and/or RTV silicone for adhesively securing various components all would be within the skill of an ordinary mechanic. The particular reed switches need not be from any particular manufacturer but are required in the sealed unit in order to maintain-the integrity of the system so that it would be free from explosive sparking. Any differences in the refuel and defuel modes could be effected by variations in the reed switch.

I claim:

1. Means for providing a switching action for a pctroleum-oil-lubricant hydrant facility pump control system having ajunction box with a removable cover body containing hinged, nonmagnetic covers for sealing openings in said cover body comprising a nonmagnetic plate having one side mounted to said cover body at an opening, a magnetic reed switch mounted to said plate on the side of said plate remote from the cover body, and

means for providing a magnetic field proximate to said magnetic reed switch for its operation, said last-mentioned means being located on said one side of said plate.

2. A device as defined in claim 1 wherein said lastmentioned means for providing a magnetic field is a permanent magnet.

3. A device as defined in claim 2 wherein said permanent magnet is fixedly secured to a cover such that movement of said cover from its open to closed position causes actuation of said magnetic reed switch from an open to a closed position, respectively, thereby providing said system with an emergency stop control where the opening of said switch opens an electrical circuit of said system.

4. A device as defined in claim 2 including means on said one side of said plate remote from said magnetic reed switch for locating said magnet to a position for closing said magnetic reed switch when said magnet is positioned on said means for locating said magnet.

5. A device as defined in claim 4 including a lanyard secured to said magnet for remote operation of said magnet to remove it from said means for locating said magnet.

6. A device as defined in claim 2 including means for indicating closure of said switch.

7. A device as defined in claim 6 wherein said means for indicating comprises a capacitor, a resistor and a light bulb in parallel with each other and in series with said magnetic reed switch.

8. A device as defined in claim 7 including a hole in said plate and lens means located at said hole and proximate to said bulb for providing a visual indication of closure of said switch when current flows therethrough.

9. A device as defined in claim 2 including gasket means on said plate, said gasket means being located to be contacted by a cover when closed. 

1. Means for providing a switching action for a petroleum-oillubricant hydrant facility pump control system having a junction box with a removable cover body containing hinged, nonmagnetic covers for sealing openings in said cover body comprising a nonmagnetic plate having one side mounted to said cover body at an opening, a magnetic reed switch mounted to said plate on the side of said plate remote from the cover body, and means for providing a magnetic field proximate to said magnetic reed switch for its operation, said last-mentioned means being located on said one side of said plate.
 2. A device as defined in claim 1 wherein said last-mentioned means for providing a magnetic field is a permanent magnet.
 3. A device as defined in claim 2 wherein said permanent magnet is fixedly secured to a cover such that movement of said cover from its open to closed position causes actuation of said magnetic reed switch from an open to a closed position, respectively, thereby providing said system with an emergency stop control where the opening of said switch opens an electrical circuit of said system.
 4. A device as defined in claim 2 including means on said one side of said plate remote from said magnetic reed switch for locating said magnet to a position for closing said magnetic reed switch when said magnet is positioned on said means for locating said magnet.
 5. A device as defined in claim 4 including a lanyard secured to said magnet for remote operation of said magnet to remove it from said means for locating said magnet.
 6. A device as defined in claim 2 including means for indicating closure of said switch.
 7. A device as defined in claim 6 wherein said means for indicating comprises a capacitor, a resistor and a light bulb in parallel with each other and in series with said magnetic reed switch.
 8. A device as defined in claim 7 including a hole in said plate and lens means located at said hole and proximate to said bulb for providing a visual indication of closure of said switch when current flows therethrough.
 9. A device as defined in claim 2 including gasket means on said plate, said gasket means being located to be contacted by a cover when closed. 